Yijing Wang [Mon, 17 Aug 2015 10:47:58 +0000 (18:47 +0800)]
PCI: Tolerate hierarchies with no Root Port
We should not assume any particular hardware topology. Commit d0751b98dfa3
("PCI: Add dev->has_secondary_link to track downstream PCIe links") relied
on the assumption that every PCIe hierarchy is rooted at a Root Port. But
we can't rely on any assumption about what hardware we will find; we just
have to deal with the world as it is.
On some platforms, PCIe devices (endpoints, switch upstream ports, etc.)
appear directly on the root bus, and there is no Root Port in the PCI bus
hierarchy. For example, Meelis observed these top-level devices on a
Sparc V245:
0000:02:00.0 PCI bridge to [bus 03-0d] Switch Upstream Port
0001:02:00.0 PCI bridge to [bus 03] PCIe to PCI/PCI-X Bridge
These devices *look* like they have links going upstream, but there really
are no upstream devices.
In set_pcie_port_type(), we used the parent device to figure out which side
of a switch port has a link, so if the parent device did not exist, we
dereferenced a NULL parent pointer.
Check whether the parent device exists before dereferencing it.
Meelis observed this oops on Sparc V245 and T2000. Ben Herrenschmidt says
this is also possible on IBM PowerVM guests on PowerPC.
Adrian Hunter [Wed, 19 Aug 2015 14:29:20 +0000 (17:29 +0300)]
perf tools: Make fork event processing more resilient
When processing a fork event, the tools lookup the parent thread by its
tid. In a couple of cases, it is possible for that thread to have the
wrong pid.
That can happen if the data is being processed out of order, or if the
(fork) event that would have removed the erroneous thread was lost.
Assume the latter case, print a dump message, remove the erroneous
thread, create a new one with the correct pid, and keep going.
Takashi Iwai [Wed, 19 Aug 2015 16:31:54 +0000 (18:31 +0200)]
Merge tag 'asoc-v4.2-disable-topology' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Disable topology support for v4.2
The topology code merged in the v4.2 merge window introduced a new ABI
which was believed to be suitable for use but subsequently additional
work by the developers of this feature have revealed some problems that
need to be addressed. In order to allow this to be done without having
to support the initial ABI add Kconfig to disable the build and also add
some #error statements to the UAPI header so users can't use them.
Takashi Iwai [Wed, 19 Aug 2015 05:20:14 +0000 (07:20 +0200)]
ALSA: usb-audio: Fix runtime PM unbalance
The fix for deadlock in PM in commit [1ee23fe07ee8: ALSA: usb-audio:
Fix deadlocks at resuming] introduced a new check of in_pm flag.
However, the brainless patch author evaluated it in a wrong way
(logical AND instead of logical OR), thus usb_autopm_get_interface()
is wrongly called at probing, leading to unbalance of runtime PM
refcount.
The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.
The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.
The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.
The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.
The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.
The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.
The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.
drm/i915: Allow parsing of variable size child device entries from VBT
That commit is not valid for v4.2, however it will be valid for v4.3. It
was simply queued too early.
The referenced regressing commit is just fine until the size of struct
common_child_dev_config changes, and that won't happen until
v4.3. Indeed, the expected size checks here rely on the increased size
of the struct, breaking new platforms.
Roland Dreier [Fri, 14 Aug 2015 04:59:19 +0000 (21:59 -0700)]
target: Fix handling of small allocation lengths in REPORT LUNS
REPORT LUNS should not fail just because the allocation length is less
than 16. The relevant section of SPC-4 is:
4.2.5.6 Allocation length
The ALLOCATION LENGTH field specifies the maximum number of bytes or
blocks that an application client has allocated in the Data-In
Buffer. The ALLOCATION LENGTH field specifies bytes unless a
different requirement is stated in the command definition.
An allocation length of zero specifies that no data shall be
transferred. This condition shall not be considered an error.
So we should just truncate our response rather than return an error.
Sven Eckelmann [Tue, 18 Aug 2015 11:37:01 +0000 (13:37 +0200)]
batman-adv: Fix memory leak on tt add with invalid vlan
The object tt_local is allocated with kmalloc and not initialized when the
function batadv_tt_local_add checks for the vlan. But this function can
only cleanup the object when the (not yet initialized) reference counter of
the object is 1. This is unlikely and thus the object would leak when the
vlan could not be found.
Instead the uninitialized object tt_local has to be freed manually and the
pointer has to set to NULL to avoid calling the function which would try to
decrement the reference counter of the not existing object.
CID: 1316518 Fixes: 354136bcc3c4 ("batman-adv: fix kernel crash due to missing NULL checks") Signed-off-by: Sven Eckelmann <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Linus Torvalds [Tue, 18 Aug 2015 19:17:36 +0000 (12:17 -0700)]
Merge tag 'dmaengine-fix-4.2-rc8' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine fix from Vinod Koul:
"We recently found issue with dma_request_slave_channel() API causing
privatecnt value to go bad. This is fixed by balancing the privatecnt"
* tag 'dmaengine-fix-4.2-rc8' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: fix balance of privatecnt inc/dec operations
Mark Brown [Tue, 18 Aug 2015 05:59:25 +0000 (22:59 -0700)]
ASoC: topology: Disable use from userspace
Since the topology API is still in sufficient flux for changes to be
identified disable the use of the userspace ABI by adding #error
statements to the code, ensuring that nobody relies on the headers as
currently defined. It is expected that this change will be reverted for
v4.3.
Jiang Liu [Tue, 18 Aug 2015 15:20:20 +0000 (23:20 +0800)]
x86/irq: Build correct vector mapping for multiple MSI interrupts
Alex Deucher, Mark Rustad and Alexander Holler reported a regression
with the latest v4.2-rc4 kernel, which breaks some SATA controllers.
With multi-MSI capable SATA controllers, only the first port works,
all other ports time out when executing SATA commands.
This happens because the first argument to assign_irq_vector_policy()
is always the base linux irq number of the multi MSI interrupt block,
so all subsequent vector assignments operate on the base linux irq
number, so all MSI irqs are handled as the first irq number. Therefor
the other MSI irqs of a device are never set up correctly and never
fire.
Add the loop iterator to the base irq number so all vectors are
assigned correctly.
Alan Stern [Mon, 17 Aug 2015 15:02:42 +0000 (11:02 -0400)]
SCSI: Fix NULL pointer dereference in runtime PM
The routines in scsi_rpm.c assume that if a runtime-PM callback is
invoked for a SCSI device, it can only mean that the device's driver
has asked the block layer to handle the runtime power management (by
calling blk_pm_runtime_init(), which among other things sets q->dev).
However, this assumption turns out to be wrong for things like the ses
driver. Normally ses devices are not allowed to do runtime PM, but
userspace can override this setting. If this happens, the kernel gets
a NULL pointer dereference when blk_post_runtime_resume() tries to use
the uninitialized q->dev pointer.
This patch fixes the problem by calling the block layer's runtime-PM
routines only if the device's driver really does have a runtime-PM
callback routine. Since ses doesn't define any such callbacks, the
crash won't occur.
Hiral Shah [Tue, 14 Jul 2015 14:08:57 +0000 (07:08 -0700)]
fnic: Use the local variable instead of I/O flag to acquire io_req_lock in fnic_queuecommand() to avoid deadloack
We added changes in fnic driver patch 1.6.0.16 to acquire
io_req_lock in fnic_queuecommand() before issuing I/O so that io completion
is serialized. But when releasing the lock we check for the I/O flag and
this could be modified if IO abort occurs before I/O completion. In this case
we wont release the lock and causes deadlock in some scenerios. Using the
local variable to check the IO lock status will resolve the problem.
Linus Torvalds [Tue, 18 Aug 2015 14:55:05 +0000 (07:55 -0700)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"These came in late last week, I wanted to look over the mst one before
forwarding, but it seems good.
Just three i915 and one MST fix"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/i915: Commit planes on each crtc separately.
drm/i915: calculate primary visibility changes instead of calling from set_config
drm/i915: Only dither on 6bpc panels
drm/dp/mst: Remove port after removing connector.
Eric Dumazet [Mon, 17 Aug 2015 17:18:48 +0000 (10:18 -0700)]
timer: Write timer->flags atomically
lock_timer_base() cannot prevent the following :
CPU1 ( in __mod_timer()
timer->flags |= TIMER_MIGRATING;
spin_unlock(&base->lock);
base = new_base;
spin_lock(&base->lock);
// The next line clears TIMER_MIGRATING
timer->flags &= ~TIMER_BASEMASK;
CPU2 (in lock_timer_base())
see timer base is cpu0 base
spin_lock_irqsave(&base->lock, *flags);
if (timer->flags == tf)
return base; // oops, wrong base
timer->flags |= base->cpu // too late
We must write timer->flags in one go, otherwise we can fool other cpus.
Masahiro Yamada [Mon, 17 Aug 2015 03:03:33 +0000 (04:03 +0100)]
ARM: 8418/1: add boot image dependencies to not generate invalid images
U-Boot is often used to boot the kernel on ARM boards, but uImage
is not built by "make all", so we are often inclined to do
"make all uImage" to generate DTBs, modules and uImage in a single
command, but we should notice a pitfall behind it. In fact,
"make all uImage" could generate an invalid uImage if it is run with
the parallel option (-j).
You can reproduce this problem with the following procedure:
[1] First, build "all" and "uImage" separately.
You will get a valid uImage
$ git clean -f -x -d
$ export CROSS_COMPILE=<your-tools-prefix>
$ make -s -j8 ARCH=arm multi_v7_defconfig
$ make -s -j8 ARCH=arm all
$ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 uImage
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
CHK include/generated/timeconst.h
CHK include/generated/bounds.h
CHK include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
CHK include/generated/compile.h
Kernel: arch/arm/boot/Image is ready
Kernel: arch/arm/boot/zImage is ready
UIMAGE arch/arm/boot/uImage
Image Name: Linux-4.2.0-rc5-00156-gdd2384a-d
Created: Sat Aug 8 23:21:35 2015
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 6138648 Bytes = 5994.77 kB = 5.85 MB
Load Address: 80208000
Entry Point: 80208000
Image arch/arm/boot/uImage is ready
$ ls -l arch/arm/boot/*Image
-rwxrwxr-x 1 masahiro masahiro 13766656 Aug 8 23:20 arch/arm/boot/Image
-rw-rw-r-- 1 masahiro masahiro 6138712 Aug 8 23:21 arch/arm/boot/uImage
-rwxrwxr-x 1 masahiro masahiro 6138648 Aug 8 23:20 arch/arm/boot/zImage
[2] Update some source file(s)
$ touch init/main.c
[3] Then, re-build "all" and "uImage" simultaneously.
You will get an invalid uImage at random.
$ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 all uImage
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
CHK include/generated/timeconst.h
CHK include/generated/bounds.h
CHK include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
CC init/main.o
CHK include/generated/compile.h
LD init/built-in.o
LINK vmlinux
LD vmlinux.o
MODPOST vmlinux.o
GEN .version
CHK include/generated/compile.h
UPD include/generated/compile.h
CC init/version.o
LD init/built-in.o
KSYM .tmp_kallsyms1.o
KSYM .tmp_kallsyms2.o
LD vmlinux
SORTEX vmlinux
SYSMAP System.map
OBJCOPY arch/arm/boot/Image
Building modules, stage 2.
Kernel: arch/arm/boot/Image is ready
GZIP arch/arm/boot/compressed/piggy.gzip
AS arch/arm/boot/compressed/piggy.gzip.o
Kernel: arch/arm/boot/Image is ready
LD arch/arm/boot/compressed/vmlinux
GZIP arch/arm/boot/compressed/piggy.gzip
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
UIMAGE arch/arm/boot/uImage
Image Name: Linux-4.2.0-rc5-00156-gdd2384a-d
Created: Sat Aug 8 23:23:14 2015
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 26472 Bytes = 25.85 kB = 0.03 MB
Load Address: 80208000
Entry Point: 80208000
Image arch/arm/boot/uImage is ready
MODPOST 192 modules
AS arch/arm/boot/compressed/piggy.gzip.o
LD arch/arm/boot/compressed/vmlinux
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
$ ls -l arch/arm/boot/*Image
-rwxrwxr-x 1 masahiro masahiro 13766656 Aug 8 23:23 arch/arm/boot/Image
-rw-rw-r-- 1 masahiro masahiro 26536 Aug 8 23:23 arch/arm/boot/uImage
-rwxrwxr-x 1 masahiro masahiro 6138648 Aug 8 23:23 arch/arm/boot/zImage
Please notice the uImage is extremely small when this issue is
encountered. Besides, "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, before and after the uImage log.
The root cause of this is the race condition between zImage and
uImage. Actually, uImage depends on zImage, but the dependency
between the two is only described in arch/arm/boot/Makefile.
Because arch/arm/boot/Makefile is not included from the top-level
Makefile, it cannot know the dependency between zImage and uImage.
Consequently, when we run make with the parallel option, Kbuild
updates vmlinux first, and then two different threads descends into
the arch/arm/boot/Makefile almost at the same time, one for updating
zImage and the other for uImage. While one thread is re-generating
zImage, the other also tries to update zImage before creating uImage
on top of that. zImage is overwritten by the slower thread and then
uImage is created based on the half-written zImage.
This is the reason why "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, and a broken uImage is created.
The same problem could happen on bootpImage.
This commit adds dependencies among Image, zImage, uImage, and
bootpImage to arch/arm/Makefile, which is included from the
top-level Makefile.
The mmap semaphore should not be taken when page faults are disabled.
Since pagefault_disable() no longer disables preemption, we now need
to use faulthandler_disabled() in place of in_atomic().
The genex.S file appears to mix the case of a macro between its definition and
use. A cut down example of this is below. The macro __build_clear_none has
lower case 'build' but ends up being instantiated with upper case BUILD. Can
this be fixed on master. It has been picked up by the LLVM integrated assembler
which is currently case sensitive. We are likely to fix the assembler as well
but the code is currently inconsistent in the kernel.
Mark Brown [Sat, 15 Aug 2015 15:24:20 +0000 (08:24 -0700)]
ASoC: topology: Add Kconfig option for topology
Allow the topology code to be compiled out so that users who don't need
topology don't need to havve the code compiled in, saving them some
memory.
Some more configuration could be added to remove some of the hooks into
the core data structures but that is probably best done with some
refactoring to use functions to do the updates of the data structures
rather than ifdefing in the code as we'd need to do at the minute.
Linus Torvalds [Mon, 17 Aug 2015 23:20:45 +0000 (16:20 -0700)]
Merge branch 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata fixes from Tejun Heo:
"Three minor device-specific fixes and revert of NCQ autosense added
during this -rc1.
It turned out that NCQ autosense as currently implemented interferes
with the usual error handling behavior. It will be revisited in the
near future"
* 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
ata: ahci_brcmstb: Fix misuse of IS_ENABLED
sata_sx4: Check return code from pdc20621_i2c_read()
Revert "libata: Implement NCQ autosense"
Revert "libata: Implement support for sense data reporting"
Revert "libata-eh: Set 'information' field for autosense"
ata: ahci_brcmstb: Fix warnings with CONFIG_PM_SLEEP=n
Linus Torvalds [Mon, 17 Aug 2015 23:15:26 +0000 (16:15 -0700)]
Merge branch 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
"A fix for a subtle bug introduced back during 3.17 cycle which
interferes with setting configurations under specific conditions"
* 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: use trialcs->mems_allowed as a temp variable
Ivan Vecera [Fri, 14 Aug 2015 20:30:01 +0000 (22:30 +0200)]
be2net: avoid vxlan offloading on multichannel configs
VxLAN offloading is not functional if the NIC is running in multichannel
mode (UMC, FLEX-10, VNIC...). Enabling this additionally kills whole
connectivity through the NIC and the device needs to be down and up to
restore it. The firmware should take care about it and does not allow
the conversion of interface to tunnel type (be_cmd_manage_iface) or should
support VxLAN offloading if multichannel config is enabled.
I have tested this on the latest available firmware (10.6.144.21).
Result:
[root@sm-04 ~]# ip link set enp5s0f0 up[root@sm-04 ~]# ip addr add 172.30.10.50/24 dev enp5s0f0
[root@sm-04 ~]# ping -c 3 172.30.10.254PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.
64 bytes from 172.30.10.254: icmp_seq=1 ttl=64 time=0.317 ms
64 bytes from 172.30.10.254: icmp_seq=2 ttl=64 time=0.187 ms
64 bytes from 172.30.10.254: icmp_seq=3 ttl=64 time=0.188 ms
--- 172.30.10.254 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.187/0.230/0.317/0.063 ms
[root@sm-04 ~]# ip link add link enp5s0f0 vxlan10 type vxlan id 10 remote 172.30.10.60 dstport 4789
[root@sm-04 ~]# ip link set vxlan10 up
[ 7900.442811] be2net 0000:05:00.0: Enabled VxLAN offloads for UDP port 4789
[ 7900.455722] be2net 0000:05:00.1: Enabled VxLAN offloads for UDP port 4789
[ 7900.468635] be2net 0000:05:00.2: Enabled VxLAN offloads for UDP port 4789
[ 7900.481553] be2net 0000:05:00.3: Enabled VxLAN offloads for UDP port 4789
[root@sm-04 ~]# ping -c 3 172.30.10.254
PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.
[root@sm-04 ~]# ip link set vxlan10 down
[ 7959.434093] be2net 0000:05:00.0: Disabled VxLAN offloads for UDP port 4789
[ 7959.444792] be2net 0000:05:00.1: Disabled VxLAN offloads for UDP port 4789
[ 7959.455592] be2net 0000:05:00.2: Disabled VxLAN offloads for UDP port 4789
[ 7959.466416] be2net 0000:05:00.3: Disabled VxLAN offloads for UDP port 4789
[root@sm-04 ~]# ip link del vxlan10
[root@sm-04 ~]# ping -c 3 172.30.10.254
PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.
[root@sm-04 ~]# ip link set enp5s0f0 down
[root@sm-04 ~]# ip link set enp5s0f0 up
[ 8071.019003] be2net 0000:05:00.0 enp5s0f0: Link is Up
[root@sm-04 ~]# ping -c 3 172.30.10.254
PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.
64 bytes from 172.30.10.254: icmp_seq=1 ttl=64 time=0.318 ms
64 bytes from 172.30.10.254: icmp_seq=2 ttl=64 time=0.196 ms
64 bytes from 172.30.10.254: icmp_seq=3 ttl=64 time=0.194 ms
--- 172.30.10.254 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.194/0.236/0.318/0.057 ms
Martin KaFai Lau [Fri, 14 Aug 2015 18:05:54 +0000 (11:05 -0700)]
ipv6: Fix a potential deadlock when creating pcpu rt
rt6_make_pcpu_route() is called under read_lock(&table->tb6_lock).
rt6_make_pcpu_route() calls ip6_rt_pcpu_alloc(rt) which then
calls dst_alloc(). dst_alloc() _may_ call ip6_dst_gc() which takes
the write_lock(&tabl->tb6_lock). A visualized version:
Martin KaFai Lau [Fri, 14 Aug 2015 18:05:53 +0000 (11:05 -0700)]
ipv6: Add rt6_make_pcpu_route()
It is a prep work for fixing a potential deadlock when creating
a pcpu rt.
The current rt6_get_pcpu_route() will also create a pcpu rt if one does not
exist. This patch moves the pcpu rt creation logic into another function,
rt6_make_pcpu_route().
Martin KaFai Lau [Fri, 14 Aug 2015 18:05:52 +0000 (11:05 -0700)]
ipv6: Remove un-used argument from ip6_dst_alloc()
After 4b32b5ad31a6 ("ipv6: Stop rt6_info from using inet_peer's metrics"),
ip6_dst_alloc() does not need the 'table' argument. This patch
cleans it up.
Igor Plyatov [Fri, 14 Aug 2015 17:11:02 +0000 (20:11 +0300)]
net: phy: workaround for buggy cable detection by LAN8700 after cable plugging
* Due to HW bug, LAN8700 sometimes does not detect presence of energy in the
Ethernet cable in Energy Detect Power-Down mode (e.g while EDPWRDOWN bit is
set, the ENERGYON bit does not asserted sometimes). This is a common bug of
LAN87xx family of PHY chips.
* The lan87xx_read_status() was improved to acquire ENERGYON bit. Its previous
algorythm still not reliable on 100 % and sometimes skip cable plugging.
Guillaume Nault [Fri, 14 Aug 2015 08:42:56 +0000 (10:42 +0200)]
ppp: fix device unregistration upon netns deletion
PPP devices may get automatically unregistered when their network
namespace is getting removed. This happens if the ppp control plane
daemon (e.g. pppd) exits while it is the last user of this namespace.
This leads to several races:
* ppp_exit_net() may destroy the per namespace idr (pn->units_idr)
before all file descriptors were released. Successive ppp_release()
calls may then cleanup PPP devices with ppp_shutdown_interface() and
try to use the already destroyed idr.
* Automatic device unregistration may also happen before the
ppp_release() call for that device gets executed. Once called on
the file owning the device, ppp_release() will then clean it up and
try to unregister it a second time.
To fix these issues, operations defined in ppp_shutdown_interface() are
moved to the PPP device's ndo_uninit() callback. This allows PPP
devices to be properly cleaned up by unregister_netdev() and friends.
So checking for ppp->owner is now an accurate test to decide if a PPP
device should be unregistered.
Setting ppp->owner is done in ppp_create_interface(), before device
registration, in order to avoid unprotected modification of this field.
Finally, ppp_exit_net() now starts by unregistering all remaining PPP
devices to ensure that none will get unregistered after the call to
idr_destroy().
Shaohui Xie [Fri, 14 Aug 2015 04:23:40 +0000 (12:23 +0800)]
net: phy: fix PHY_RUNNING in phy_state_machine
Currently, if phy state is PHY_RUNNING, we always register a CHANGE
when phy works in polling or interrupt ignored, this will make the
adjust_link being called even the phy link did Not changed.
checking the phy link to make sure the link did changed before we
register a CHANGE, if link did not changed, we do nothing.
Calvin Owens [Thu, 13 Aug 2015 21:21:34 +0000 (14:21 -0700)]
Revert "net: limit tcp/udp rmem/wmem to SOCK_{RCV,SND}BUF_MIN"
Commit 8133534c760d4083 ("net: limit tcp/udp rmem/wmem to
SOCK_{RCV,SND}BUF_MIN") modified four sysctls to enforce that the values
written to them are not less than SOCK_MIN_{RCV,SND}BUF.
That change causes 4096 to no longer be accepted as a valid value for
'min' in tcp_wmem and udp_wmem_min. 4096 has been the default for both
of those sysctls for a long time, and unfortunately seems to be an
extremely popular setting. This change breaks a large number of sysctl
configurations at Facebook.
That commit referred to b1cb59cf2efe7971 ("net: sysctl_net_core: check
SNDBUF and RCVBUF for min length"), which choose to use the SOCK_MIN
constants as the lower limits to avoid nasty bugs. But AFAICS, a limit
of SOCK_MIN_SNDBUF isn't necessary to do that: the BUG_ON cited in the
commit message seems to have happened because unix_stream_sendmsg()
expects a minimum of a full page (ie SK_MEM_QUANTUM) and the math broke,
not because it had less than SOCK_MIN_SNDBUF allocated.
This particular issue doesn't seem to affect TCP however: using a
setting of "1 1 1" for tcp_{r,w}mem works, although it's obviously
suboptimal. SK_MEM_QUANTUM would be a nice minimum, but it's 64K on
some archs, so there would still be breakage.
Since a value of one doesn't seem to cause any problems, we can drop the
minimum 8133534c added to fix this.
Robert Baldyga [Fri, 7 Aug 2015 10:26:47 +0000 (12:26 +0200)]
dmaengine: fix balance of privatecnt inc/dec operations
This patch increments privatecnt value and set DMA_PRIVATE in device
caps in dma_request_slave_channel() function. This is needed to keep
privatecnt increment/decrement balance.
As function dma_release_channel() decrements privatecnt counter, we need
to increment it when channel is requested. Otherwise privatecnt drops
into negatives after few dma_release_channel() calls.
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- a regression caused by the conversion of IPsec ESP to the new AEAD
interface: ESN with authencesn no longer works because it relied on
the AD input SG list having a specific layout which is no longer
the case. In linux-next authencesn is fixed properly and no longer
assumes anything about the SG list format. While for this release
a minimal fix is applied to authencesn so that it works with the
new linear layout.
- fix memory corruption caused by bogus index in the caam hash code.
- fix powerpc nx SHA hashing which could cause module load failures
if module signature verification is enabled"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: caam - fix memory corruption in ahash_final_ctx
crypto: nx - respect sg limit bounds when building sg lists for SHA
crypto: authencesn - Fix breakage with new ESP code
Chris Wilson [Fri, 14 Aug 2015 11:59:19 +0000 (12:59 +0100)]
drm/i915: Flag the execlists context object as dirty after every use
Everytime we use the logical context with execlists it becomes dirty (as
the hardware will write the new register values afterwards, as well as
the GPU state that will be used). We need to then flag the context as
dirty everytime since after a swap-out/swap-in cycle the dirty flag will
be cleared, and a further swap-out cycle will then loose the most recent
GPU state.
Linus Torvalds [Sun, 16 Aug 2015 22:44:33 +0000 (15:44 -0700)]
Merge tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"A smallish batch of fixes, a little more than expected this late, but
all fixes are contained to their platforms and seem reasonably low
risk:
- a somewhat large SMP fix for ux500 that still seemed warranted to
include here
- OMAP DT fixes for pbias regulator specification that broke due to
some DT reshuffling
- PCIe IRQ routing bugfix for i.MX
- networking fixes for keystone
- runtime PM for OMAP GPMC
- a couple of error path bug fixes for exynos"
* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file
ARM: dts: keystone: fix the clock node for mdio
memory: omap-gpmc: Don't try to save uninitialized GPMC context
ARM: imx6: correct i.MX6 PCIe interrupt routing
ARM: ux500: add an SMP enablement type and move cpu nodes
ARM: dts: dra7: Fix broken pbias device creation
ARM: dts: OMAP5: Fix broken pbias device creation
ARM: dts: OMAP4: Fix broken pbias device creation
ARM: dts: omap243x: Fix broken pbias device creation
ARM: EXYNOS: fix double of_node_put() on error path
ARM: EXYNOS: Fix potentian kfree() of ro memory
Linus Torvalds [Sun, 16 Aug 2015 22:11:25 +0000 (15:11 -0700)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Merge x86 fixes from Ingo Molnar:
"Two followup fixes related to the previous LDT fix"
Also applied a further FPU emulation fix from Andy Lutomirski to the
branch before actually merging it.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
x86/ldt: Further fix FPU emulation
x86/ldt: Correct FPU emulation access to LDT
x86/ldt: Correct LDT access in single stepping logic
Olof Johansson [Sun, 16 Aug 2015 19:29:57 +0000 (21:29 +0200)]
Merge tag 'keystone-dts-late-fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone into fixes
ARM: Couple of Keysyone MDIO DTS fixes for 4.2-rc6+
These are necessary to get the NIC card working on all Keystone
EVMs. Couple of boards are broken without these two fixes.
* tag 'keystone-dts-late-fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone:
ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file
ARM: dts: keystone: fix the clock node for mdio
Markos Chandras [Thu, 13 Aug 2015 07:47:59 +0000 (08:47 +0100)]
MIPS: Fix seccomp syscall argument for MIPS64
Commit 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)")
fixed indirect system calls on O32 but it also introduced a bug for MIPS64
where it erroneously modified the v0 (syscall) register with the assumption
that the sycall offset hasn't been taken into consideration. This breaks
seccomp on MIPS64 n64 and n32 ABIs. We fix this by replacing the addition
with a move instruction.
Linus Torvalds [Sat, 15 Aug 2015 20:54:53 +0000 (13:54 -0700)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"This has two libfc fixes for bugs causing rare crashes, one iscsi fix
for a potential hang on shutdown, and a fix for an I/O blocksize issue
which caused a regression"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
sd: Fix maximum I/O size for BLOCK_PC requests
libfc: Fix fc_fcp_cleanup_each_cmd()
libfc: Fix fc_exch_recv_req() error path
libiscsi: Fix host busy blocking during connection teardown
Dave Airlie [Sat, 15 Aug 2015 04:51:31 +0000 (14:51 +1000)]
Merge tag 'drm-intel-fixes-2015-08-14' of git://anongit.freedesktop.org/drm-intel into drm-next
three display fixes for Intel.
* tag 'drm-intel-fixes-2015-08-14' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Commit planes on each crtc separately.
drm/i915: calculate primary visibility changes instead of calling from set_config
drm/i915: Only dither on 6bpc panels
thermal/cpu_cooling: update policy limits if clipped_freq < policy->max
policy->max is the maximum allowed frequency defined by user and
clipped_freq is the maximum that thermal constraints allow.
If clipped_freq is lower than policy->max, then we need to readjust
policy->max.
But, if clipped_freq is greater than policy->max, we don't need to do
anything. We used to call cpufreq_verify_within_limits() in this case,
but it doesn't change anything in this case.
Lets skip this unnecessary call and write a comment that explains this.
thermal/cpu_cooling: convert 'switch' block to 'if' block in notifier
We just need to take care of single event here and there is no need to
increase indentation level of most of the code (which causes lines
longer that 80 columns to break).
thermal/cpu_cooling: quit early after updating policy
If a valid cpufreq_dev is found for policy->cpu, we should update the
policy and quit the for loop. There is no need to keep traversing the
list of cpufreq_dev's.
Russell King [Wed, 12 Aug 2015 09:52:16 +0000 (15:22 +0530)]
thermal: cpu_cooling: fix lockdep problems in cpu_cooling
A recent change to the cpu_cooling code introduced a AB-BA deadlock
scenario between the cpufreq_policy_notifier_list rwsem and the
cooling_cpufreq_lock. This is caused by cooling_cpufreq_lock being held
before the registration/removal of the notifier block (an operation
which takes the rwsem), and the notifier code itself which takes the
locks in the reverse order:
======================================================
[ INFO: possible circular locking dependency detected ]
3.18.0+ #1453 Not tainted
-------------------------------------------------------
rc.local/770 is trying to acquire lock:
(cooling_cpufreq_lock){+.+.+.}, at: [<c04abfc4>] cpufreq_thermal_notifier+0x34/0xfc
but task is already holding lock:
((cpufreq_policy_notifier_list).rwsem){++++.+}, at: [<c0042f04>] __blocking_notifier_call_chain+0x34/0x68
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
Solve this by moving to finer grained locking - use one mutex to protect
the cpufreq_dev_list as a whole, and a separate lock to ensure correct
ordering of cpufreq notifier registration and removal.
cooling_list_lock is taken within cooling_cpufreq_lock on
(un)registration to preserve the behavior of the code, i.e. to
atomically add/remove to the list and (un)register the notifier.
Linus Torvalds [Sat, 15 Aug 2015 00:27:52 +0000 (17:27 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Just two very small & simple patches"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: Use adjustment in guest cycles when handling MSR_IA32_TSC_ADJUST
KVM: x86: zero IDT limit on entry to SMM
Linus Torvalds [Sat, 15 Aug 2015 00:05:26 +0000 (17:05 -0700)]
Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
"11 fixes"
* emailed patches from Andrew Morton <[email protected]>:
Update maintainers for DRM STI driver
mm: cma: mark cma_bitmap_maxno() inline in header
zram: fix pool name truncation
memory-hotplug: fix wrong edge when hot add a new node
.mailmap: Andrey Ryabinin has moved
ipc/sem.c: update/correct memory barriers
mm/hwpoison: fix panic due to split huge zero page
ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()
ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits
mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held
mm/hwpoison: fix page refcount of unknown non LRU page
Gregory Fong [Fri, 14 Aug 2015 22:35:21 +0000 (15:35 -0700)]
mm: cma: mark cma_bitmap_maxno() inline in header
cma_bitmap_maxno() was marked as static and not static inline, which can
cause warnings about this function not being used if this file is included
in a file that does not call that function, and violates the conventions
used elsewhere. The two options are to move the function implementation
back to mm/cma.c or make it inline here, and it's simple enough for the
latter to make sense.
However, it defines pool name buffer to be only 8 bytes long (minus
trailing zero), which means that we can have only 1000 pool names: zram0
-- zram999.
With CONFIG_ZSMALLOC_STAT enabled an attempt to create a device zram1000
can fail if device zram100 already exists, because snprintf() will
truncate new pool name to zram100 and pass it debugfs_create_dir(),
causing:
debugfs dir <zram100> creation failed
zram: Error creating memory pool
... and so on.
Fix it by passing zram->disk->disk_name to zram_meta_alloc() instead of
divice_id. We construct zram%d name earlier and keep it as a ->disk_name,
no need to snprintf() it again.
Xishi Qiu [Fri, 14 Aug 2015 22:35:16 +0000 (15:35 -0700)]
memory-hotplug: fix wrong edge when hot add a new node
When we add a new node, the edge of memory may be wrong.
e.g. system has 4 nodes, and node3 is movable, node3 mem:[24G-32G],
1. hotremove the node3,
2. then hotadd node3 with a part of memory, mem:[26G-30G],
3. call hotadd_new_pgdat()
free_area_init_node()
get_pfn_range_for_nid()
4. it will return wrong start_pfn and end_pfn, because we have not
update the memblock.
This patch also fixes a BUG_ON during hot-addition, please see
http://marc.info/?l=linux-kernel&m=142961156129456&w=2
Manfred Spraul [Fri, 14 Aug 2015 22:35:10 +0000 (15:35 -0700)]
ipc/sem.c: update/correct memory barriers
sem_lock() did not properly pair memory barriers:
!spin_is_locked() and spin_unlock_wait() are both only control barriers.
The code needs an acquire barrier, otherwise the cpu might perform read
operations before the lock test.
As no primitive exists inside <include/spinlock.h> and since it seems
noone wants another primitive, the code creates a local primitive within
ipc/sem.c.
With regards to -stable:
The change of sem_wait_array() is a bugfix, the change to sem_lock() is a
nop (just a preprocessor redefinition to improve the readability). The
bugfix is necessary for all kernels that use sem_wait_array() (i.e.:
starting from 3.10).
Huge zero page is allocated if page fault w/o FAULT_FLAG_WRITE flag.
The get_user_pages_fast() which called in madvise_hwpoison() will get
huge zero page if the page is not allocated before. Huge zero page is a
tranparent huge page, however, it is not an anonymous page.
memory_failure will split the huge zero page and trigger
BUG_ON(is_huge_zero_page(page));
After commit 98ed2b0052e6 ("mm/memory-failure: give up error handling
for non-tail-refcounted thp"), memory_failure will not catch non anon
thp from madvise_hwpoison path and this bug occur.
Fix it by catching non anon thp in memory_failure in order to not split
huge zero page in madvise_hwpoison path.
After this patch:
Injecting memory failure for page 0x202800 at 0x7fd8ae800000
MCE: 0x202800: non anonymous thp
[...]
ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()
After we acquire the sma->sem_perm lock in exit_sem(), we are protected
against a racing IPC_RMID operation. Also at that point, we are the last
user of sem_undo_list. Therefore it isn't required that we acquire or use
ulp->lock.
ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits
The current semaphore code allows a potential use after free: in
exit_sem we may free the task's sem_undo_list while there is still
another task looping through the same semaphore set and cleaning the
sem_undo list at freeary function (the task called IPC_RMID for the same
semaphore set).
For example, with a test program [1] running which keeps forking a lot
of processes (which then do a semop call with SEM_UNDO flag), and with
the parent right after removing the semaphore set with IPC_RMID, and a
kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and
CONFIG_DEBUG_SPINLOCK, you can easily see something like the following
in the kernel log:
I wasn't able to trigger any badness on a recent kernel without the
proper config debugs enabled, however I have softlockup reports on some
kernel versions, in the semaphore code, which are similar as above (the
scenario is seen on some servers running IBM DB2 which uses semaphore
syscalls).
The patch here fixes the race against freeary, by acquiring or waiting
on the sem_undo_list lock as necessary (exit_sem can race with freeary,
while freeary sets un->semid to -1 and removes the same sem_undo from
list_proc or when it removes the last sem_undo).
After the patch I'm unable to reproduce the problem using the test case
[1].
void create_set()
{
int i, j;
pid_t p;
union {
int val;
struct semid_ds *buf;
unsigned short int *array;
struct seminfo *__buf;
} un;
/* Create and initialize semaphore set */
for (i = 0; i < NSET; i++) {
sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT);
if (sid[i] < 0) {
perror("semget");
exit(EXIT_FAILURE);
}
}
un.val = 0;
for (i = 0; i < NSET; i++) {
for (j = 0; j < NSEM; j++) {
if (semctl(sid[i], j, SETVAL, un) < 0)
perror("semctl");
}
}
/* Launch threads that operate on semaphore set */
for (i = 0; i < NSEM * NSET * NSET; i++) {
p = fork();
if (p < 0)
perror("fork");
if (p == 0)
thread();
}
/* Free semaphore set */
for (i = 0; i < NSET; i++) {
if (semctl(sid[i], NSEM, IPC_RMID))
perror("IPC_RMID");
}
/* Wait for forked processes to exit */
while (wait(NULL)) {
if (errno == ECHILD)
break;
};
}
int main(int argc, char **argv)
{
pid_t p;
srand(time(NULL));
while (1) {
p = fork();
if (p < 0) {
perror("fork");
exit(EXIT_FAILURE);
}
if (p == 0) {
create_set();
goto end;
}
/* Wait for forked processes to exit */
while (wait(NULL)) {
if (errno == ECHILD)
break;
};
}
end:
return 0;
}
Wanpeng Li [Fri, 14 Aug 2015 22:34:59 +0000 (15:34 -0700)]
mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held
Hugetlbfs pages will get a refcount in get_any_page() or
madvise_hwpoison() if soft offlining through madvise. The refcount which
is held by the soft offline path should be released if we fail to isolate
hugetlbfs pages.
Fix it by reducing the refcount for both isolation success and failure.
Wanpeng Li [Fri, 14 Aug 2015 22:34:56 +0000 (15:34 -0700)]
mm/hwpoison: fix page refcount of unknown non LRU page
After trying to drain pages from pagevec/pageset, we try to get reference
count of the page again, however, the reference count of the page is not
reduced if the page is still not on LRU list.
Fix it by adding the put_page() to drop the page reference which is from
__get_any_page().
Linus Torvalds [Fri, 14 Aug 2015 18:06:43 +0000 (11:06 -0700)]
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
"A single clocksource driver suspend/resume fix"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clockevents/drivers/sh_cmt: Only perform clocksource suspend/resume if enabled
Linus Torvalds [Fri, 14 Aug 2015 17:39:32 +0000 (10:39 -0700)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"Back from holidays, found these in the cracks: one nouveau revert, one
vmwgfx locking fix and a bunch of exynos fixes"
Hans de Goede [Thu, 13 Aug 2015 16:53:37 +0000 (18:53 +0200)]
ACPI / video: Fix circular lock dependency issue in the video-detect code
Before this commit, the following would happen:
a) acpi_video_get_backlight_type() gets called
b) acpi_video_get_backlight_type() calls acpi_video_init_backlight_type()
c) acpi_video_init_backlight_type() locks its function static init_mutex
d) acpi_video_init_backlight_type() calls backlight_register_notifier()
e) backlight_register_notifier() takes its notifier-chain lock
And when the backlight notifier chain gets called we've:
1) blocking_notifier_call_chain() gets called
2) blocking_notifier_call_chain() takes the notifier-chain lock
3) blocking_notifier_call_chain() calls acpi_video_backlight_notify()
4) acpi_video_backlight_notify() calls acpi_video_get_backlight_type()
5) acpi_video_get_backlight_type() calls acpi_video_init_backlight_type()
6) acpi_video_init_backlight_type() locks its function static init_mutex
So in the first call sequence we have:
a) init_mutex gets locked
b) notifier-chain gets locked
And we've a circular locking dependency. This specific locking dependency
is fixable without using the big hammer otherwise known as a workqueue,
but further analysis shows a similar problem with the backlight notifier
chain lock vs register_count_mutex from drivers/acpi/acpi_video.c,
and fixing that becomes problematic.
So this commit simply fixes this with the big hammer, performance
wise this is a non issue as we expect the work to get scheduled
exactly zero or one times during normal system use.
Fixes: 93a291dfaf9c (ACPI / video: Move backlight notifier to video_detect.c) Signed-off-by: Hans de Goede <[email protected]> Reported-and-tested-by: Sedat Dilek <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>
Eric Dumazet [Thu, 13 Aug 2015 22:44:51 +0000 (15:44 -0700)]
inet: fix potential deadlock in reqsk_queue_unlink()
When replacing del_timer() with del_timer_sync(), I introduced
a deadlock condition :
reqsk_queue_unlink() is called from inet_csk_reqsk_queue_drop()
inet_csk_reqsk_queue_drop() can be called from many contexts,
one being the timer handler itself (reqsk_timer_handler()).
In this case, del_timer_sync() loops forever.
Simple fix is to test if timer is pending.
Fixes: 2235f2ac75fd ("inet: fix races with reqsk timers") Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Claudiu Manoil [Thu, 13 Aug 2015 13:50:37 +0000 (16:50 +0300)]
gianfar: Restore link state settings after MAC reset
There are some MAC registers that need to be kept in sync
with the link state parameters, see adjust_link().
However, after a MAC soft reset default values for
these registers are assumed. In some cases (excepting
if down/ if up for example) adjust_link() does not see
that these values were reset to default because the
priv->old* link parameters were left unchanged.
So, reset the priv->old* link params as well during a
MAC reset to let adjust_link() restore the MAC link
settings to the actual link state values.
Fixes following case, for example:
Setting link to 100M, changing MTU (implies MAC reset),
link state remains unchanged to 100M but MAC registers
were reset to default (1G) breaking the connectivity w/
the PHY. Closing and re-opening the interface would
restore the MAC link parameters to the correct values.
Andy Whitcroft [Thu, 13 Aug 2015 19:49:01 +0000 (20:49 +0100)]
ipv4: off-by-one in continuation handling in /proc/net/route
When generating /proc/net/route we emit a header followed by a line for
each route. When a short read is performed we will restart this process
based on the open file descriptor. When calculating the start point we
fail to take into account that the 0th entry is the header. This leads
us to skip the first entry when doing a continuation read.
This can be easily seen with the comparison below:
while read l; do echo "$l"; done </proc/net/route >A
cat /proc/net/route >B
diff -bu A B | grep '^[+-]'
On my example machine I have approximatly 10KB of route output. There we
see the very first non-title element is lost in the while read case,
and an entry around the 8K mark in the cat case:
The recent refactoring of the IGMP and MLD parsing code into
ipv6_mc_check_mld() / ip_mc_check_igmp() introduced a potential crash /
BUG() invocation for bridges:
I wrongly assumed that skb_get() could be used as a simple reference
counter for an skb which is not the case. skb_get() bears additional
semantics, a user count. This leads to a BUG() invocation in
pskb_expand_head() / kernel panic if pskb_may_pull() is called on an skb
with a user count greater than one - unfortunately the refactoring did
just that.
Fixing this by removing the skb_get() call and changing the API: The
caller of ipv6_mc_check_mld() / ip_mc_check_igmp() now needs to
additionally check whether the returned skb_trimmed is a clone.
This commit seems to cause crashes in gk104_fifo_intr_runlist() by
returning 0xbad0da00 when register 0x2a00 is read. Since this commit was
intended for GM20B which is not completely supported yet, let's revert
it for the time being.